Electric terminal protection



Aug. 21, 1956 H. C. CUNNINGHAM ELECTRIC TERMINAL PROTECTION Filed Feb. 9, 1953' HHRRY C. CUNNINGHFIM United States Patent ELECTRIC TERMINAL PROTECTION Harry C. Cunningham, Pittsburgh, Pa., assignor to Edwin L. Wiegand Company, Pittsburgh, Pa., a corporation of Pennsylvania Application February 9, 1953, Serial No. 335,654

4 Claims. (Cl. 339-76) My invention relates to means for protecting an electric terminal, more particularly to means for protecting the terminal connections of range-type sheathed electric heating elements from contact with portions of the range or with each other, and the principal object of my invention is to provide new and improved means of the character described.

In the past, the terminal connections of range-type sheathed electric heating units have been secured to a terminal block by means of screws. However, these terminal blocks are troublesome to install and they do not offer complete protection to the terminals since they are usually open at the bottom to facilitate assembly.

My invention completely protects the terminals of a sheathed electric heating element and it may be installed much more quickly and economically than those of the prior art. These and other advantages will become apparent from a study of the following description and from the drawing appended hereto.

In the drawing accompanying this specification and forming a part of this application there is shown, for purpose of illustration, an embodiment which my invention may assume, and in this drawing:

Figure 1 is a perspective view of my invention secured in position to a fragmentarily shown, sheathed electric range-type heating element of conventional design,

Figure 2 is an enlarged perspective view of a detail, and

Figure 3 is an enlarged view generally corresponding to the line 33 of Figure 1.

.As shown in the drawing, my invention is presently adapted for use with a sheathed range-type electric heating element having four terminal portions to which connections must be made. However, it will be apparent that my invention may be adapted for use with heating elements other than of range-type and with elements having any number ofterminal connections.

.As is well known in the art, :the common range type sheathed electric heating element generally comprises a pair of convoluted, sheathed heating elements secured together to form a generally plane support for the container to be heated. The convoluted portions of the heating elements are usually supported by a spider that in turn is supported by the range, and the elements are usually secured to the spider to form a unitary structure. The ends 10, 11, 12 and 13 of the heating elements are generally disposed together in side-by-side relation as shown, to facilitate making the necessary electrical connections.

In the present embodiment and as illustrated in Figures 2 and 3, a terminal pin 14 extends axially from each of the ends 10, 11, 12 and 13 of the sheathed heating elements. Each terminal pin 14 is adapted to be secured to the conventional resistance wire contained within the sheath and a terminal lug 15 is adapted to be electrically and mechanically secured to each terminal pin 14, as shown, by any suitable means.

Each terminal lug 15 is narrowed at 16 to provide a shoulder 17 for a purpose to be shown. Insulated elec- 2,760,173 Patented Aug. 21,1956

tric power leads 18 are adapted to be connected to the terminal lugs 15, and as illustrated in Figure 2, each lead 18 is electrically connected to a channel-like clip or connect-or 19. In the present embodiment one of the leads '18 has .two clips 19 secured thereto since this lead is common to both elements.

As will be apparent, each clip 19 is adapted to he slid over a respective terminal lug 15 until it engages the shoulder 17, the clip 19 being so constructed and proportioned that frictional interengagement between the clip and the lug is sufficient to insure good electrical contact therebetween.

My invention provides means for protecting the above described electrical connections and to this end-I provide a dielectric body 28 which completely covers the said electrical connection-s. In the present embodiment, the body 20 comprises two complementarily formed pieces 21 and 22 held together by means of a spring clip 23.

In the present embodiment each piece 21, 22 forms one-half of the body 20, each being similar to the other with the exception that the pieces are of opposite hand. Each piece is formed with semi-circular recesses 24, the recesses in the pieces combining to form openings for receiving the spaced-apart terminal portions 10, 11, 12 and 13 of the heating elements. The body portion to each piece is further recessed to provide a hollow interior 25 for the body 20, this hollow interior receiving the terminal pins 14, terminal lugs 15, clips 19 and leads 18.

As illustrated, the end 10 of the heating element does not project as far into the interior of the body 20 as do the ends '11, 12 and 13, and the terminal pins 14 of the ends 12 and 13 are longer than those of ends 10 and '11. This arrangement staggers the position of the lugs 15 within the body 20 for a purpose to appear.

Walls 26 and 27, formed in part in each of the body pieces '21, 22, divide the chamber 25 and these walls effectively separate the electrical connections and eliminate the possibility of shorts therebetween. Each wall 26, 27 is provided with a transversely disposed foot 28, and these feet 28 and a wall 29 which defines the hollow interior 25 of the body 20, prevent disengagement of respective clips.1 9 from the lugs 15. An elongated aperture 30 leads from an outer edge of the body 20 tothe interior thereof, this aperture 30 being adapted to pass the electric leads 18.

Means are provided to restrict axial movement of the body 20 with respect to the ends of the heating elements and such means presently comprises a wall 31 that -is disposed between the end 10 of the heating element and its respective iterminal lug 15. The wall 31 is defined by wall portions :carried by the respective body pieces "21, 22,.eachiwall portion being recessed and'together providing an aperture to pass the terminal pin 14. It will be clear that once the two pieces 21, 22 of the body 20 are secured in position, movement of the body 20 in an axial direction will be restricted by interengagement of the wall 31 with either the end 10 of the heating element or the lug 15 carried by the end 10.

Additionally, movement of the end of the body 20 adjacent element end 13 is limited in one direction by engagement of the clip 19 carried by element end 13 with the wall 29, and in the other direction by engagement of the lug 15 carried by element end 13 with a wall 27a. As will be understood, the wall 27a is in part provided by each of the pieces 21, 22 and each wall portion is recessed at 27b to pass the terminal pin 14 that extends from this element end. A foot portion 28a is provided by each wall portion 27a and this foot serves to maintain the spacing between element ends 12, 13.

Although the pieces 21, 22 of the body 20 have been shown and described as being similar but of the opposite hand, it is to be understood that if desired only one of the pieces could be formed as described While the other piece could simply be a flat closure plate. It is also to be understood that means other than the spring clip 23 may be employed to hold the two pieces of the body 20 together.

In view of the foregoing it will be apparent to those skilled in the art that I have accomplished at least the principal object of my invention and it will also be apparent to those skilled in the'art that the embodiment herein described may be variously changed and modified, without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described, hence it will be appreciated that the herein disclosed embodiment is illustrative only, and that my invention is not limited thereto.

I claim:

1. In combination with a sheathed electric heating element having a current-carrying terminal pin extending axially from the end of said sheath, a slip-on electrical connector adapted to be electrically connected to said terminal pin by shifting it axially thereof in a direction toward said sheath, and means for protecting the exposed current-carrying portion of said heating element, comprising a dielectric body having an internal cavity for receiv ing the end of said sheath, said terminal pin and the connector secured thereto, said body being formed of separable portions which together substantially completely encase the current-carrying terminal portion of said heating element, interengageable means in part provided by said heating element and in part provided by said body to restrict movement of said body in either direction axially of said heating element, abutment means provided by said body adjacent said electrical connector to prevent axial movement of the latter in a direction away from said sheath and consequent, disengagement thereof from said terminal pin, and means for holding said portions of said body together.

2. In combination with a sheathed electric heating element having a current-carrying terminal pin extending axially from the end of said sheath, said terminal pin having a terminal lug secured thereto in spaced relation with respect to the end of said sheath, and means for protecting the exposed current-carrying portion of said heating element, comprising a dielectric body having an internal cavity for receiving the end of said sheath, said terminal pin and said terminal lug, said body being formed of separable portions which together substantially completely encase the current-carrying portion of said heating element and said body having a portion disposed between the end of said sheath and an adjacent portion of said terminal lug to restrict movement of said body axially of said heating element, and means for holding said portions of said body together.

3. In combination with a sheathed electric heating element formed with its ends disposed in side-by-side relation and having a current-carrying terminal pin extending axially from each end of said sheath, a terminal lug secured to each terminal pin in spaced relation to a respective end of said sheath, a slip-on electrical connector for each of said terminal lugs, each connector being engageable with its respective terminal lug by shifting it axially of said terminal pin, and means for protecting the exposed current-carrying terminal portion of said heating element, comprising a dielectric body having spacedapart internal cavities for receiving respective end-s of said sheath, said terminal pins and the parts secured thereto, said body being formed of separable portions which together substantially completely encase the current-carrying terminal portion of said heating element, interengageable means in part provided by said heating element and in part provided by said body to restrict movement of said body axially of said heating element, abutment means provided by said body adjacent said electrical connectors to prevent disengagement of said connectors from respective terminal lugs, and means for holding said portions of said body together.

4. In combination with a sheathed electric heating element formed with its ends disposed in side-by-side relation and having a current-carrying terminal pin extending axially from each end of said sheath, 2. terminal lug secured to each terminal pin in spaced relation to a respective end of said sheath, a slip-on electrical connector for each of said terminal lugs, each connector being engageable' with its respective terminal lug by shifting it axially of said terminal pin, and'means for protecting the exposed current-carrying terminal portion of said heating element, comprising a dielectric body having spaced-apart internal cavities for receiving respective ends of said sheath, said terminal pins and the parts secured thereto, said body being formed of separable portions which together substantially completely encase the current-carrying terminal portion of said heating element and said body having a portion disposed between one of the ends of said sheath and an adjacent portion of a respective terminal lug to restrict movement of said body axially of said heating element, abutment means provided by said body adjacent said electrical connectors to prevent disengagement of said connectors from respective terminal lugs, and means for holding said portions of said body together.

References Cited in the file of this patent UNITED STATES PATENTS 931,573 Crawford Aug. 17, 1909 1,674,253 Lightfioot June 19, 1928 2,281,515 Ruggieri Apr. 28, 1942 2,465,540 Korn Mar. 29, 1949 2,600,188 Batcheller June 10, 1952 FOREIGN PATENTS 667,685 Great Britain Mar. 5, 1952 

